Field microscope



FIG. 1 is a front elevation of a field microscope showing my new design;

FIG. 2 is an elevation of the right end of the microscope as seen in FIG. 1;

FIG. 3 is a rear elevation thereof;

FIG. 4 is an elevation of the left end thereof as seen in FIG. 1;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a field microscope, as shown. 